Traditionally, electrical connectors having a split electrical connector housing comprise a first housing independent from a second housing. The split electrical connector housing creates a connection between mated connectors for a wire harness in use in an automobile and the like. As more sensors are being installed in automobiles, the number of electrical connectors needed for wire harnesses also increases. Consequently, a greater number of electrical connectors must be mated with their counterparts in an automobile assembly line, which results in lower productivity.
Japanese Patent Application Publication No. 2003-331989 discloses a technique to prevent incorrect connection between the first and second housings of the electrical connector. In Japanese Patent Application Publication No. 2002-231372 the electrical connector has a common second housing that can receive different types of first housings. However, when one or more of the first housings are accommodated in the second housing in a different assembly line, partially inserted first housings can still pass a continuity test. Because the first housings are not fully inserted, the connection can become further disengaged due to later occurring vibrations.
Various techniques have been proposed to detect partial insertion of an electrical connector in a mating connector. For example, Japanese Patent Application Publication No. 9-251876 discloses a structure wherein contacts provided in a housing of each of the connectors are not connected to their counterpart until the connectors are fully mated with each other. When the contacts are connected, an electric circuit is actuated to detect complete mating of the connectors. While it is possible to employ such a technique to the first housing and the second housing of an electrical connector having a split electrical connector housing, the installation of a detecting circuit would unduly complicate the configuration of the electrical connector.